1. Field of the Invention
The present invention concerns a process and a device for the measurement and processing in real time of the level changes which may occur between two or more points in a structure, building, machinery or the like, specially during works of civil engineering directly or indirectly involving the same. Typical examples of said applications can be found in tunnel workings, where phenomena of surface draw can take place related to the changes in the ground tensive state, in particular changes induced works of injection and/or consolidation. The importance of such draws obviously varies in proportion to the distance of the considered points from the tunnel and to several other factors; in urban areas, in any case, said distance is necessarily reduced and therefore there is the need of controlling the effects that said draws have on the buildings located near the tunnel, as the distortions caused may involve structural lesions of considerable importance and even affect the stability of the buildings themselves. The same types of draws can affect the correct positioning of machinery, for instance digging machines.
2. Description of the Prior Art
A possible control consists in using techniques which optimize the operative modes of said workings, but said techniques present a too high degree of approximation, mainly in urban areas, and therefore cannot represent a sufficiently valid method for controlling said phenomena. It is therefore necessary to find a system for controlling and measuring in real time said draw, in order to allow to take in due time the appropriate measures. For this reason, and in any case to maintain the control on the conditions of buildings or machinery during digging operations, as well as for other applications in civil engineering field, so-called communicating vessel level meters are used. Said communicating vessel level meters allow the continuous measurement of differential changes of level in a number of points or stations, between one another or with respect to the level of one station taken as a reference point. The disadvantage of said system lies in the fact that, as indicated by its name, it works according to the principle of the communicating vessels; the system therefore needs a certain number of vessels (one for each station) which must be closed and provided with instruments, partially filled with a liquid and communicating by means of a double connection (liquid side and gas side), as obtained by one or more ducts which must be installed horizontally or, when this is not possible, must be provided with special devices compensating the non horizontal development of the system. The resulting system is consequently rigid and complicated, and its extremely difficult installation makes the use thereof not suitable for limited periods of time, such as those involved during urban workings.